Acute Stimulation of Albumin Synthesis Rate with Oral Meal Feeding in Healthy Subjects Measured with [Ring-2H5]Phenylalanine

1995 ◽  
Vol 88 (2) ◽  
pp. 235-242 ◽  
Author(s):  
K. A. Hunter ◽  
P. E. Ballmer ◽  
S. E. Anderson ◽  
J. Broom ◽  
P. J. Garlick ◽  
...  
Keyword(s):  
Oral Feeding ◽  
Synthesis Rate ◽  
Liver Protein ◽  
Albumin Synthesis ◽  
Adult Rats ◽  
Fed State ◽  
Total Liver ◽  
Fractional Rate ◽  
Fractional Synthesis ◽  
Stimulation Of

1. The short-term effect of oral feeding on albumin synthesis rate was investigated in 12 healthy volunteers using two meal regimens. Albumin synthesis was measured over 90 min after injection of a ‘flooding’ amount (43 mg/kg body weight) of phenylalanine enriched to 7.5, 10 or 15 atoms% with the stable isotope [ring-2H5]phenylalanine. 2. In one set of subjects, consumption of five small hourly meals resulted in a consistent and significant increase (P < 0.05) in albumin fractional synthesis rate from a mean (± SEM) fasting value of 5.8 (± 0.4)%/day to 7.1 (± 0.4)%/day in the fed state. 3. A second study in which albumin synthesis was measured 30 min after consumption of a single larger meal was carried out in another set of volunteers. The fractional rate of albumin synthesis was again significantly elevated after feeding (P < 0.05), rising from 7.1 (± 0.4)%/day in the fasted state to 9.1 (± 0.6)%/day in the fed state. In both studies, similar responses were observed in the absolute rate of albumin synthesis (mg day−1 kg−1). 4. Albumin secretion time was significantly shorter (P < 0.05) after feeding in both studies, suggesting that the acute stimulation in albumin synthesis observed after feeding may in part be mediated via a post-transcriptional mechanism. 5. The response of total liver protein synthesis to oral feeding was investigated in an animal model employing adult rats studied with a flooding amount of [2,6-3H]phenylalanine. 6. The results indicated a stimulation of 20% with no difference in the proportion of albumin synthesis relative to total liver synthesis, determined from the immunoprecipitation of albumin from the liver.

scholarly journals Synthesis rate of plasma albumin is a good indicator of liver albumin synthesis in sepsis

2000 ◽  
Vol 279 (2) ◽  
pp. E244-E251 ◽  
Author(s):  
Benoît Ruot ◽  
Denis Breuillé ◽  
Fabienne Rambourdin ◽  
Gerard Bayle ◽  
Pierre Capitan ◽  
...  
Keyword(s):  
Synthesis Rate ◽  
Albumin Concentration ◽  
Liver Protein ◽  
Mrna Levels ◽  
Albumin Synthesis ◽  
Plasma Albumin ◽  
Period 2 ◽  
Fractional Synthesis ◽  
Plasma Albumin Concentration

Plasma albumin is well known to decrease in response to inflammation. The rate of albumin synthesis from both liver and plasma was measured in vivo by use of a large dose ofl-[2H3-14C]valine in rats injected intravenously with live Escherichia coli and in pair-fed control rats during the acute-phase period (2 days postinfection). The plasma albumin concentration was reduced by 50% in infected rats compared with pair-fed animals. Infection induced a fall in both liver albumin mRNA levels and albumin synthesis relative to total liver protein synthesis. However, absolute liver albumin synthesis rate (ASR) was not affected by infection. In plasma, albumin fractional synthesis rate was increased by 50% in infected animals compared with pair-fed animals. The albumin ASR estimated in the plasma was similar in the two groups. These results suggest that hypoalbuminemia is not due to reduced albumin synthesis during sepsis. Moreover, liver and plasma albumin ASR were similar. Therefore, albumin synthesis measured in the plasma is a good indicator of liver albumin synthesis.

Synthesis rates of total liver protein and albumin are both increased in patients with an acute inflammatory response

2005 ◽  
Vol 110 (1) ◽  
pp. 93-99 ◽  
Author(s):  
Hans Barle ◽  
Folke Hammarqvist ◽  
Bo Westman ◽  
Maria Klaude ◽  
Olav Rooyackers ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Laparoscopic Cholecystectomy ◽  
Acute Inflammation ◽  
Reference Group ◽  
Synthesis Rate ◽  
Control Group ◽  
Liver Protein ◽  
Total Liver ◽  
Elective Laparoscopic Cholecystectomy ◽  
Fractional Synthesis

The general perception that catabolism and inflammation are associated with a high synthesis rate of total liver protein and a low albumin synthesis rate has been challenged in recent years by several studies in man, indicating that the synthesis rate of albumin in response to a catabolic insult is increased rather than decreased. Thus changes in liver protein synthesis rates in conjunction with catabolism and acute inflammation in man need to be characterized better. The aim of the present study was to measure protein synthesis rates of total liver protein and albumin during a state of acute inflammation. Patients (n=10) undergoing acute laparoscopic cholecystectomy due to acute cholecystitis were investigated. FSRs (fractional synthesis rates) of total liver protein (liver biopsy specimens) and albumin (plasma samples) were investigated as early as possible during the surgical procedure, using a flooding dose of L-[2H5]phenylalanine. The results were compared with a reference group of patients without cholecystitis undergoing elective laparoscopic cholecystectomy (n=17). FSR of total liver protein was 60% higher (P<0.001) and the FSR of albumin was 45% higher (P<0.01) in the cholecystitis patients compared with the control group. In conclusion, the synthesis rates of total liver protein and albumin are both increased in patients with an acute general inflammatory reaction undergoing laparoscopic cholecystectomy.

Albumin synthesis in humans increases immediately following the administration of endotoxin

2002 ◽  
Vol 103 (5) ◽  
pp. 525-531 ◽  
Author(s):  
Hans BARLE ◽  
Anna JANUSZKIEWICZ ◽  
Lars HÅLLSTRÖM ◽  
Pia ESSÉN ◽  
Margaret A. MCNURLAN ◽  
...  
Keyword(s):  
Intravenous Injection ◽  
Early Phase ◽  
The Other ◽  
Synthesis Rate ◽  
Control Group ◽  
Albumin Synthesis ◽  
Fractional Synthesis Rate ◽  
Before And After ◽  
Fractional Synthesis ◽  
Absolute Synthesis

In order to investigate the immediate (i.e. within 3h) response of albumin synthesis to the administration of endotoxin, as a model of a moderate and well controlled catabolic insult, two measurements employing L-[2H5]phenylalanine were performed in 16 volunteers. One group (n = 8) received an intravenous injection of endotoxin (4ng/kg; lot EC-6) immediately after the first measurement of albumin synthesis, whereas the other group received saline. A second measurement was initiated 1h later. In the endotoxin group, the fractional synthesis rate of albumin was 6.9±0.6%/day (mean±S.D.) in the first measurement. In the second measurement, a significant increase was observed (9.6±1.2%/day; P<0.001). The corresponding values in the control group were were 6.6±0.6%/day and 7.0±0.6%/day respectively (not significant compared with first measurement and P<0.001 compared with the second measurement in the endotoxin group). The absolute synthesis rates of albumin were 148±35 and 201±49mg·kg-1·day-1 before and after endotoxin (P<0.01). In the control group, the corresponding values were 131±21 and 132±20mg·kg-1·day-1 (not significant compared with the first measurement and P<0.01 compared with the second measurement in the endotoxin group). In conclusion, these results indicate that albumin synthesis increases in the very early phase after a catabolic insult, as represented by the administration of endotoxin.

Inhibition of liver protein synthesis during laparoscopic surgery

1999 ◽  
Vol 277 (4) ◽  
pp. E591-E596 ◽  
Author(s):  
Hans Barle ◽  
Björn Nyberg ◽  
Stig Ramel ◽  
Pia Essén ◽  
Margaret A. McNurlan ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Laparoscopic Surgery ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Liver Protein ◽  
Early Group ◽  
Total Liver ◽  
Elective Laparoscopic Cholecystectomy ◽  
Absolute Synthesis ◽  
Late Group

Previous studies have indicated that laparoscopic surgery is associated with a decline in liver protein synthesis. In this study, the fractional synthesis rate (FSR) of total liver protein and albumin was measured in patients undergoing elective laparoscopic cholecystectomy at different times after commencing the procedure ( n = 8 + 8). Liver biopsy specimens were taken after 15 min of surgery in an “early” group and after 49 min of surgery in a “late” group. The liver FSR was higher in the early group (24.1 ± 4.7%/day) compared with the late group (19.0 ± 2.8%/day, P < 0.02). The fractional and absolute synthesis rates of albumin were similar in the two groups, 6.4 ± 1.5 vs. 6.5 ± 1.0%/day and 97 ± 19 vs. 96 ± 18 mg ⋅ kg−1⋅ day−1for the early and late groups, respectively. It is concluded that laparoscopic surgery was accompanied by a decrease in total liver protein synthesis rate, which developed rapidly during surgery. In contrast, no change in the synthesis rate of albumin was apparent during the course of surgery.

scholarly journals Myofibrillar protein turnover. Synthesis of protein-bound 3-methylhistidine, actin, myosin heavy chain and aldolase in rat skeletal muscle in the fed and starved states

1983 ◽  
Vol 214 (2) ◽  
pp. 593-605 ◽  
Author(s):  
P C Bates ◽  
G K Grimble ◽  
M P Sparrow ◽  
D J Millward
Keyword(s):  
Skeletal Muscle ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Similar Rate ◽  
Synthesis Rate ◽  
Turnover Rates ◽  
Adult Rats ◽  
Fed State ◽  
Mixed Protein ◽  
Slow Turnover

The turnover of 3-methylhistidine (N tau-methylhistidine) and in some cases actin, myosin heavy chain and aldolase in skeletal muscle was measured in a number of experiments in growing and adult rats in the fed and overnight-starved states. In growing fed rats in three separate experiments, measurements of the methylation rate of protein-bound 3-methylhistidine by either [14C]- or [3H]-methyl-labelled S-adenosylmethionine show that 3-methylhistidine synthesis is slower than the overall rate of protein synthesis indicated by [14C]tyrosine incorporation. Values ranged from 36 to 51%. However, in one experiment with rapidly growing young fed rats, acute measurements over 1 h showed that 3-methylhistidine synthesis could be increased to the same rate as the overall rate. After overnight starvation in these rats, the steady-state synthesis rate of 3-methylhistidine was 38.8% of the overall rate. This was a similar value to that in adult non-growing rats, in which measurements of the relative labelling of 3-methylhistidine and histidine after a single injection of [14C]histidine indicated that 3-methylhistidine synthesis was 37% of the overall rate in the fed or overnight-starved state. According to measurements of actin, myosin heavy-chain and aldolase synthesis in the over-night-starved state with young rats, with a variety of precursors, slow turnover of 3-methylhistidine results from the specific slow turnover of actin, since turnover rates of myosin heavy chain, mixed protein and aldolase were 2.5, 3 and 3.4 times faster respectively. However, in the fed state synthesis rates of actin were increased disproportionately to give similar rates for all proteins. These results show that (a) 3-methylhistidine turnover in muscle is less than half the overall rate in both young and adult rats, (b) slow 3-methylhistidine turnover reflects the specifically slow turnover of actin compared with myosin heavy chain and other muscle proteins, and (c) during growth the synthesis rate of actin is particularly sensitive to the nutritional state and can be increased to a similar rate to that of other proteins.

Protein metabolism in skin and muscle of sheep selected for or against staple strength

2000 ◽  
Vol 51 (5) ◽  
pp. 541 ◽  
Author(s):  
N. R. Adams ◽  
S. M. Liu ◽  
J. R. Briegel ◽  
J. C. Greeff
Keyword(s):  
Growth Rate ◽  
Protein Synthesis ◽  
Synthesis Rate ◽  
Deuterated Water ◽  
Feeding Level ◽  
Fractional Rate ◽  
Wool Growth ◽  
Fractional Synthesis ◽  
Selection For ◽  
Staple Strength

Two experiments were carried out to determine the mechanisms underlying the reduced effect of nutritional status on wool growth rate in Merino sheep that have been selected for high staple strength (SS). In Expt 1, each group of 6 young sheep of SS+ and SS– genotypes were fed at 0.4 or 1.1 times maintenance, and in Expt 2, groups of 8 sheep of each genotype were fed at 1.1 and 1.8 times maintenance. In both experiments, rates of protein synthesis in skin, muscle, gut, rumen, and liver were determined using a flooding dose of labelled phenylalanine. Feed intake and the digestibility of feed were not affected by genotype. Neither dissection of the carcasses at slaughter, nor deuterated water analysis in Expt 1, detected any differences between the genotypes in body composition. The feeding level affected the total daily amount of protein synthesised in all the organs examined, and the fractional rate of protein synthesis was affected by feeding level in all organs except the liver. The fractional synthesis rate of protein was less responsive to feeding level in the SS+ sheep in both skin and muscle (P < 0.05), but not in the liver, jejunum, or rumen. Total protein synthesis in muscle, and the estimated rate of protein degradation, were also less responsive to feeding level in the SS+ sheep (P < 0.05). We conclude that sheep genetically selected for high or low SS have altered local mechanisms in both skin and muscle that control the way they respond to nutrition. These findings provide a mechanism by which selection for wool growth rate also affects body metabolism.

scholarly journals Effects of trenbolone acetate and zeranol on protein metabolism in male castrate andfemale lambs

1983 ◽  
Vol 50 (2) ◽  
pp. 225-234 ◽  
Author(s):  
Patrick A. Sinnett-Smith ◽  
Nicola W. Dumelow ◽  
Peter J. Buttery
Keyword(s):  
Growth Rate ◽  
Conversion Efficiency ◽  
Cathepsin D ◽  
Muscle Protein ◽  
Synthesis Rate ◽  
Liver Protein ◽  
Trenbolone Acetate ◽  
Fractional Synthesis ◽  
Plasma Leucine ◽  
Cathepsin D Activity

1. Tissue composition and skeletal muscle cathepsin D (EC 3.4.23.5) activity weremeasured in wether lambs treated with trenbolone acetate (TBA) and oestradiol-17β (Oe) in combination and female lambs treated with TBA or zeranol. Muscle and liver protein fractional synthesis rates and plasma leucine flux were measured in the female lambs.2. Male castrate lambs treated with TBA plus Oe showed increased growth rate, improvedfood conversion efficiency, decreased muscle RNA concentration and decreased total cathepsin D activity in muscle.3. Female lambs treated with TBA or zeranol showed increased weight gain, improved food conversion efficiency, decreased muscle RNA and DNA concentrations and decreased free cathepsin D activity in muscle. Mixed muscle protein fractional synthesis rate was decreasedafter TBA treatment. Plasma leucine flux, not corrected for oxidation or food intake, wasnot increased by TBA or zeranol treatment.4. Treatment of female lambs with TBA or zeranol caused increased growth rate. This increased growth rate is probably due in part to decreased muscle protein degradation, since evidence was obtained that muscle protein synthesis is decreased by TBA and zeranol treatment.

Liver albumin synthesis in sepsis in the rat: influence of parenteral nutrition, glutamine and growth hormone

2003 ◽  
Vol 105 (6) ◽  
pp. 691-698 ◽  
Author(s):  
Michael J. O'LEARY ◽  
Michael KOLL ◽  
Colin N. FERGUSON ◽  
John H. COAKLEY ◽  
Charles J. HINDS ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Protein Synthesis ◽  
Parenteral Nutrition ◽  
Acute Phase Proteins ◽  
Statistical Significance ◽  
Synthesis Rate ◽  
Albumin Synthesis ◽  
Fractional Rate ◽  
Caecal Ligation And Puncture ◽  
Hepatic Protein Synthesis

The effect of sepsis on liver synthesis of albumin remains controversial, with studies in man suggesting that synthesis increases, whereas in animals increased, decreased and unaltered synthesis have been reported. To reconcile these conflicting data, total and relative albumin synthesis was measured in rats 24 h after caecal ligation and puncture (CLP) by immunoprecipitation of albumin following a flooding dose of L-[4-3H]phenylalanine. Following CLP, animals were starved for 18 h and then received intravenous infusions of saline or parenteral nutrition (PN) with or without glutamine for 6 h. In animals receiving PN, parenteral injections of growth hormone (GH) or saline vehicle were also administered. Fractional rate of liver total protein synthesis was elevated and total albumin synthesis rate was reduced in all CLP groups when compared with non-operated animals. Total albumin synthesis was also lower in all animals receiving PN than those receiving saline alone, although these differences did not attain statistical significance, except for the group receiving PN+GH. Relative albumin synthesis was also reduced after CLP, and was significantly lower in animals receiving PN than in those receiving saline alone. These findings suggest that in sepsis hepatic protein synthesis is reprioritized away from the production of albumin towards the production of acute-phase proteins and that this change is not influenced by the provision of nutritional support, glutamine or the administration of GH.

scholarly journals The effects of endotoxaemia on protein metabolism in skeletal muscle and liver of fed and fasted rats

1986 ◽  
Vol 235 (2) ◽  
pp. 329-336 ◽  
Author(s):  
M M Jepson ◽  
J M Pell ◽  
P C Bates ◽  
D J Millward
Keyword(s):  
Protein Synthesis ◽  
Protein Metabolism ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Synthesis Rate ◽  
Liver Protein ◽  
Fractional Synthesis Rate ◽  
Protein Mass ◽  
Fractional Synthesis ◽  
Fasted Rats

The response of muscle and liver protein metabolism to either a single or three successive daily injections of an endotoxin (Escherichia coli lipopolysaccharide, serotype 0127 B8; 1 mg/ml, 0.3 mg/100 g body wt.) was studied in vivo in the fed rat, and at 24 and 30 h after endotoxin treatment during fasting. In the fed rats there was a catabolic response in muscle, owing to a 60-100% increase in muscle protein degradation rate, and a 52% fall in the synthesis rate. Although there was a 20% decrease in food intake, the decrease in protein synthesis was to some extent independent of this, since rats treated with endotoxin and fasted also showed a lower rate of muscle protein synthesis, which was in excess of the decrease caused by fasting alone. The mechanism of this decreased protein synthesis involved decreased translational activity, since in both fed and fasted rats there was a decreased rate of synthesis per unit of RNA. This occurred despite the fact that insulin concentrations were either maintained or increased, in the fasted rats, to those observed in fed rats. In the liver total protein mass was increased in the fed rats by 16% at 24 h, and the fractional synthesis rate at that time was increased by 35%. In rats fasted after endotoxin treatment the liver protein mass was not decreased as it was in the control fasted rats, and the fractional synthesis rate was increased by 22%. In both cases the increased synthesis rate reflected an elevated hepatic RNA concentration. The extent of this increase in hepatic protein synthesis was sufficient at one point to compensate for the fall in estimated muscle protein synthesis, so that the sum total in the two tissues was maintained.

Liver export protein synthetic rates are increased by oral meal feeding in weight-losing cancer patients

2000 ◽  
Vol 279 (3) ◽  
pp. E707-E714 ◽  
Author(s):  
Matthew D. Barber ◽  
Kenneth C. H. Fearon ◽  
Donald C. McMillan ◽  
Christine Slater ◽  
James A. Ross ◽  
...  
Keyword(s):  
Cancer Patients ◽  
Synthesis Rate ◽  
Similar Degree ◽  
Albumin Concentration ◽  
Fibrinogen Concentration ◽  
Albumin Synthesis ◽  
Fed State ◽  
Synthetic Rate ◽  
Export Protein ◽  
Median Weight Loss

We have demonstrated previously that, in the fasting state, whereas albumin synthesis is similar in cachectic cancer patients compared with controls, fibrinogen synthesis is increased. Whether synthesis of these proteins is altered after an oral meal was examined in eight weight-losing pancreatic cancer patients and six healthy controls by use of an intravenous flooding dose of [2H5]- or [2H8]phenylalanine. Cancer patients had a median weight loss of 19%, a significantly lower serum albumin concentration, and a significantly higher plasma fibrinogen concentration than controls ( P < 0.005). Fasting albumin synthesis rates were similar between cancer patients and controls (median total synthesis rate 11.3 vs. 13.9 g/day, respectively) and rose on feeding by a similar degree (median 29 and 24%). The fasting fibrinogen total synthetic rate was significantly higher in cancer patients than in controls (median 3.3 vs. 1.0 g/day, P = 0.0019). In cancer patients in the fed state, fibrinogen synthetic rate rose by a median of 38% ( P = 0.012), whereas in controls there was no significant change. These findings demonstrate significant upregulation by feeding of acute-phase protein synthesis in cachectic cancer patients.

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